This can either be good, or it can be the complete opposite. It's one thing if it was a Joker-centric movie, but this is also an origin movie for him, and that's a problem, because the main appeal of the Joker as a character is his mystique. While there are versions of the Joker that had an origin, none of them are particularly as interesting and terrifying as the versions where Joker did not have an origin. It was a genius move on Nolan's part to actually have Joker as a force of nature rather than a character you can understand fully and sympathize with.